1. Field of the Invention
The present invention relates to a vehicle outside mirror device in which a mirror assembly is rotatably mounted to a shaft via a buffering mechanism.
2. Description of the Related Art
A vehicle outside mirror device of such type is conventionally known (for example, Japanese Unexamined Patent Application Publication No. 2011-201447). Hereinafter, a conventional vehicle outside mirror device will be described. The conventional vehicle outside mirror device is provided in such a manner that when a force that is equal to or greater than an electrically driven rotation force is applied to a mirror assembly that is positioned in a use location from the use location to a forward tilt location, the mirror assembly rotates for the sake of buffering.
In the vehicle outside mirror device as described above, when the mirror assembly that has rotated from the use location to the forward tilt location for the sake of buffering is restored from the forward tilt location to the use location, it is important that the mirror assembly precisely returns to the use location without any positional shift. The conventional vehicle outside mirror device as described previously is also provided in such a manner that at a design stage, a frictional force between an interposed member and a shaft is greater than a frictional force between the interposed member and a gear case; and therefore, the interposed member and the shaft fail to slide, and the interposed member and the gear case slide. In this manner, when the mirror assembly is rotated and restored from the forward tilt location to the use location, the mirror assembly can be precisely restored to the use location without any positional shift.
However, the conventional vehicle outside mirror device described previously has entailed a problem insofar that there may be a case in which the frictional force between the interposed member and the gear case becomes greater than the frictional force between the interposed member and the shaft, depending on a state of lubricating oil, a surface state of its related components, or a biting state of a foreign matter or the like. In this case, the interposed member and the shaft slide, the interposed member and the gear case do not slide, and an engagement protrusion portion of the interposed member and the engagement recessed portion of the gear case fails to appropriately engage with each other, and when the mirror assembly is rotated and restored from the forward tilt location to the use location, there may be a case in which the use location in which the mirror assembly stops is positionally shifted.